Clients implementing this editor input interface should override
Object.equals(Object) to answer true for two inputs
that are the same. The IWorkbenchPage.openEditor APIs
are dependent on this to find an editor with the same input.

Path-oriented editors should support this as a valid input type, and
can allow full read-write editing of its content.

All editor inputs must implement the IAdaptable interface;
extensions are managed by the platform's adapter manager.